1 /*
2 * SysDB - src/frontend/grammar.y
3 * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 %{
30 #include "frontend/connection-private.h"
31 #include "frontend/parser.h"
32 #include "frontend/grammar.h"
34 #include "core/store.h"
35 #include "core/store-private.h"
37 #include "utils/error.h"
38 #include "utils/llist.h"
40 #include <stdio.h>
41 #include <string.h>
43 int
44 sdb_fe_yylex(YYSTYPE *yylval, YYLTYPE *yylloc, sdb_fe_yyscan_t yyscanner);
46 sdb_fe_yyextra_t *
47 sdb_fe_yyget_extra(sdb_fe_yyscan_t scanner);
49 void
50 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
52 /* quick access to the current parse tree */
53 #define pt sdb_fe_yyget_extra(scanner)->parsetree
55 /* quick access to the parser mode */
56 #define parser_mode sdb_fe_yyget_extra(scanner)->mode
58 %}
60 %pure-parser
61 %lex-param {sdb_fe_yyscan_t scanner}
62 %parse-param {sdb_fe_yyscan_t scanner}
63 %locations
64 %error-verbose
65 %expect 0
66 %name-prefix "sdb_fe_yy"
68 %union {
69 const char *sstr; /* static string */
70 char *str;
72 sdb_data_t data;
74 sdb_llist_t *list;
75 sdb_conn_node_t *node;
77 sdb_store_matcher_t *m;
78 sdb_store_expr_t *expr;
79 }
81 %start statements
83 %token SCANNER_ERROR
85 %token AND OR IS NOT MATCHING FILTER
86 %token CMP_EQUAL CMP_NEQUAL CMP_REGEX CMP_NREGEX
87 %token CMP_LT CMP_LE CMP_GE CMP_GT
88 %token CONCAT
90 /* NULL token */
91 %token NULL_T
93 %token FETCH LIST LOOKUP
95 %token <str> IDENTIFIER STRING
97 %token <data> INTEGER FLOAT
99 /* Precedence (lowest first): */
100 %left OR
101 %left AND
102 %right NOT
103 %left CMP_EQUAL CMP_NEQUAL
104 %left CMP_LT CMP_LE CMP_GE CMP_GT
105 %nonassoc CMP_REGEX CMP_NREGEX
106 %left CONCAT
107 %nonassoc IS
108 %left '+' '-'
109 %left '*' '/' '%'
110 %left '(' ')'
111 %left '.'
113 %type <list> statements
114 %type <node> statement
115 fetch_statement
116 list_statement
117 lookup_statement
118 matching_clause
119 filter_clause
120 condition
122 %type <m> matcher
123 compare_matcher
125 %type <expr> expression
127 %type <sstr> op
129 %type <data> data
130 interval interval_elem
132 %destructor { free($$); } <str>
133 %destructor { sdb_object_deref(SDB_OBJ($$)); } <node> <m> <expr>
135 %%
137 statements:
138 statements ';' statement
139 {
140 /* only accept this in default parse mode */
141 if (parser_mode != SDB_PARSE_DEFAULT) {
142 sdb_fe_yyerror(&yylloc, scanner,
143 YY_("syntax error, unexpected statement, "
144 "expecting condition"));
145 sdb_object_deref(SDB_OBJ($3));
146 YYABORT;
147 }
149 if ($3) {
150 sdb_llist_append(pt, SDB_OBJ($3));
151 sdb_object_deref(SDB_OBJ($3));
152 }
153 }
154 |
155 statement
156 {
157 /* only accept this in default parse mode */
158 if (parser_mode != SDB_PARSE_DEFAULT) {
159 sdb_fe_yyerror(&yylloc, scanner,
160 YY_("syntax error, unexpected statement, "
161 "expecting condition"));
162 sdb_object_deref(SDB_OBJ($1));
163 YYABORT;
164 }
166 if ($1) {
167 sdb_llist_append(pt, SDB_OBJ($1));
168 sdb_object_deref(SDB_OBJ($1));
169 }
170 }
171 |
172 condition
173 {
174 /* only accept this in condition parse mode */
175 if (! (parser_mode & SDB_PARSE_COND)) {
176 sdb_fe_yyerror(&yylloc, scanner,
177 YY_("syntax error, unexpected condition, "
178 "expecting statement"));
179 sdb_object_deref(SDB_OBJ($1));
180 YYABORT;
181 }
183 if ($1) {
184 sdb_llist_append(pt, SDB_OBJ($1));
185 sdb_object_deref(SDB_OBJ($1));
186 }
187 }
188 ;
190 statement:
191 fetch_statement
192 |
193 list_statement
194 |
195 lookup_statement
196 |
197 /* empty */
198 {
199 $$ = NULL;
200 }
201 ;
203 /*
204 * FETCH <hostname> [FILTER <condition>];
205 *
206 * Retrieve detailed information about a single host.
207 */
208 fetch_statement:
209 FETCH STRING filter_clause
210 {
211 $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
212 conn_fetch_t, conn_fetch_destroy));
213 CONN_FETCH($$)->name = strdup($2);
214 CONN_FETCH($$)->filter = CONN_MATCHER($3);
215 $$->cmd = CONNECTION_FETCH;
216 free($2); $2 = NULL;
217 }
218 ;
220 /*
221 * LIST <type> [FILTER <condition>];
222 *
223 * Returns a list of all hosts in the store.
224 */
225 list_statement:
226 LIST IDENTIFIER filter_clause
227 {
228 /* TODO: support other types as well */
229 if (strcasecmp($2, "hosts")) {
230 char errmsg[strlen($2) + 32];
231 snprintf(errmsg, sizeof(errmsg),
232 YY_("unknown data-source %s"), $2);
233 sdb_fe_yyerror(&yylloc, scanner, errmsg);
234 free($2); $2 = NULL;
235 sdb_object_deref(SDB_OBJ($3));
236 YYABORT;
237 }
239 $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
240 conn_list_t, conn_list_destroy));
241 CONN_LIST($$)->filter = CONN_MATCHER($3);
242 $$->cmd = CONNECTION_LIST;
243 free($2); $2 = NULL;
244 }
245 ;
247 /*
248 * LOOKUP <type> MATCHING <condition> [FILTER <condition>];
249 *
250 * Returns detailed information about <type> matching condition.
251 */
252 lookup_statement:
253 LOOKUP IDENTIFIER matching_clause filter_clause
254 {
255 /* TODO: support other types as well */
256 if (strcasecmp($2, "hosts")) {
257 char errmsg[strlen($2) + 32];
258 snprintf(errmsg, sizeof(errmsg),
259 YY_("unknown data-source %s"), $2);
260 sdb_fe_yyerror(&yylloc, scanner, errmsg);
261 free($2); $2 = NULL;
262 sdb_object_deref(SDB_OBJ($3));
263 sdb_object_deref(SDB_OBJ($4));
264 YYABORT;
265 }
267 $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
268 conn_lookup_t, conn_lookup_destroy));
269 CONN_LOOKUP($$)->matcher = CONN_MATCHER($3);
270 CONN_LOOKUP($$)->filter = CONN_MATCHER($4);
271 $$->cmd = CONNECTION_LOOKUP;
272 free($2); $2 = NULL;
273 }
274 ;
276 matching_clause:
277 MATCHING condition { $$ = $2; }
278 |
279 /* empty */ { $$ = NULL; }
281 filter_clause:
282 FILTER condition { $$ = $2; }
283 |
284 /* empty */ { $$ = NULL; }
286 /*
287 * Basic expressions.
288 */
290 condition:
291 matcher
292 {
293 if (! $1) {
294 /* TODO: improve error reporting */
295 sdb_fe_yyerror(&yylloc, scanner,
296 YY_("syntax error, invalid condition"));
297 YYABORT;
298 }
300 $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
301 conn_matcher_t, conn_matcher_destroy));
302 $$->cmd = CONNECTION_EXPR;
303 CONN_MATCHER($$)->matcher = $1;
304 }
305 ;
307 matcher:
308 '(' matcher ')'
309 {
310 $$ = $2;
311 }
312 |
313 matcher AND matcher
314 {
315 $$ = sdb_store_con_matcher($1, $3);
316 sdb_object_deref(SDB_OBJ($1));
317 sdb_object_deref(SDB_OBJ($3));
318 }
319 |
320 matcher OR matcher
321 {
322 $$ = sdb_store_dis_matcher($1, $3);
323 sdb_object_deref(SDB_OBJ($1));
324 sdb_object_deref(SDB_OBJ($3));
325 }
326 |
327 NOT matcher
328 {
329 $$ = sdb_store_inv_matcher($2);
330 sdb_object_deref(SDB_OBJ($2));
331 }
332 |
333 compare_matcher
334 {
335 $$ = $1;
336 }
337 ;
339 /*
340 * <object_type>.<object_attr> <op> <value>
341 *
342 * Parse matchers comparing object attributes with a value.
343 */
344 compare_matcher:
345 ':' IDENTIFIER op expression
346 {
347 $$ = sdb_store_matcher_parse_field_cmp($2, $3, $4);
348 free($2); $2 = NULL;
349 sdb_object_deref(SDB_OBJ($4));
350 }
351 |
352 IDENTIFIER op expression
353 {
354 $$ = sdb_store_matcher_parse_cmp($1, NULL, $2, $3);
355 free($1); $1 = NULL;
356 sdb_object_deref(SDB_OBJ($3));
357 }
358 |
359 IDENTIFIER '.' IDENTIFIER op expression
360 {
361 $$ = sdb_store_matcher_parse_cmp($1, $3, $4, $5);
362 free($1); $1 = NULL;
363 free($3); $3 = NULL;
364 sdb_object_deref(SDB_OBJ($5));
365 }
366 |
367 IDENTIFIER '.' IDENTIFIER IS NULL_T
368 {
369 $$ = sdb_store_matcher_parse_cmp($1, $3, "IS", NULL);
370 free($1); $1 = NULL;
371 free($3); $3 = NULL;
372 }
373 |
374 IDENTIFIER '.' IDENTIFIER IS NOT NULL_T
375 {
376 sdb_store_matcher_t *m;
377 m = sdb_store_matcher_parse_cmp($1, $3, "IS", NULL);
378 free($1); $1 = NULL;
379 free($3); $3 = NULL;
381 /* sdb_store_inv_matcher return NULL if m==NULL */
382 $$ = sdb_store_inv_matcher(m);
383 sdb_object_deref(SDB_OBJ(m));
384 }
385 ;
387 expression:
388 '(' expression ')'
389 {
390 $$ = $2;
391 }
392 |
393 expression '+' expression
394 {
395 $$ = sdb_store_expr_create(SDB_DATA_ADD, $1, $3);
396 sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
397 sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
398 }
399 |
400 expression '-' expression
401 {
402 $$ = sdb_store_expr_create(SDB_DATA_SUB, $1, $3);
403 sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
404 sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
405 }
406 |
407 expression '*' expression
408 {
409 $$ = sdb_store_expr_create(SDB_DATA_MUL, $1, $3);
410 sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
411 sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
412 }
413 |
414 expression '/' expression
415 {
416 $$ = sdb_store_expr_create(SDB_DATA_DIV, $1, $3);
417 sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
418 sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
419 }
420 |
421 expression '%' expression
422 {
423 $$ = sdb_store_expr_create(SDB_DATA_MOD, $1, $3);
424 sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
425 sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
426 }
427 |
428 ':' IDENTIFIER
429 {
430 int field = sdb_store_parse_field_name($2);
431 free($2); $2 = NULL;
432 $$ = sdb_store_expr_fieldvalue(field);
433 }
434 |
435 data
436 {
437 $$ = sdb_store_expr_constvalue(&$1);
438 sdb_data_free_datum(&$1);
439 }
440 ;
442 op:
443 CMP_EQUAL { $$ = "="; }
444 |
445 CMP_NEQUAL { $$ = "!="; }
446 |
447 CMP_REGEX { $$ = "=~"; }
448 |
449 CMP_NREGEX { $$ = "!~"; }
450 |
451 CMP_LT { $$ = "<"; }
452 |
453 CMP_LE { $$ = "<="; }
454 |
455 CMP_GE { $$ = ">="; }
456 |
457 CMP_GT { $$ = ">"; }
458 ;
460 data:
461 STRING { $$.type = SDB_TYPE_STRING; $$.data.string = $1; }
462 |
463 INTEGER { $$ = $1; }
464 |
465 FLOAT { $$ = $1; }
466 |
467 interval { $$ = $1; }
468 ;
470 interval:
471 interval interval_elem
472 {
473 $$.data.datetime = $1.data.datetime + $2.data.datetime;
474 }
475 |
476 interval_elem { $$ = $1; }
477 ;
479 interval_elem:
480 INTEGER IDENTIFIER
481 {
482 sdb_time_t unit = 1;
484 unit = sdb_strpunit($2);
485 if (! unit) {
486 char errmsg[strlen($2) + 32];
487 snprintf(errmsg, sizeof(errmsg),
488 YY_("invalid time unit %s"), $2);
489 sdb_fe_yyerror(&yylloc, scanner, errmsg);
490 free($2); $2 = NULL;
491 YYABORT;
492 }
493 free($2); $2 = NULL;
495 $$.type = SDB_TYPE_DATETIME;
496 $$.data.datetime = (sdb_time_t)$1.data.integer * unit;
498 if ($1.data.integer < 0) {
499 sdb_fe_yyerror(&yylloc, scanner,
500 YY_("syntax error, negative intervals not supported"));
501 YYABORT;
502 }
503 }
504 ;
506 %%
508 void
509 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg)
510 {
511 sdb_log(SDB_LOG_ERR, "frontend: parse error: %s", msg);
512 } /* sdb_fe_yyerror */
514 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */